Final answer:
he correct answer to this question is b) Contractile ring. The formation of the contractile ring, which will eventually form the new cell walls of the daughter cells, is directed by FtsZ. In prokaryotes, this ring is known as the Z ring and it constricts to divide the cell into two. The divisome, which includes the Z ring, is responsible for building the cell wall septum that separates daughter cells.
Step-by-step explanation:
FtsZ proteins are essential for bacterial cell division and are involved in the assembly of a structure known as the Z ring. This Z ring is critical in prokaryotic cytokinesis, as it constricts to partition the cell into two daughter cells.
During cell division, the division septum is formed, where the new cell walls of the daughter cells are created. The Z ring, guided by FtsZ and anchored by FtsZ-binding proteins, defines the division plane between daughter cells. Along with other proteins, it forms the divisome, which facilitates the construction of the peptidoglycan cell wall and the development of a septum that will separate the two emerging cells.
It is noteworthy that while eukaryotic cells use microtubules composed of tubulin for their mitotic spindle apparatus during cell division, prokaryotic cells use FtsZ proteins to assemble the Z ring, reflecting a functional similarity between the two protein structures. Hence, the spindle fibers (comprising microtubules and related to tubulin) mentioned in option 'a' and mitotic spindle apparatus relate more to eukaryote cell division processes and not the role of FtsZ in prokaryotes.